Switchboard for telephones.



Bunn. SWITCHBOABD FR TELEPHONES. (Apphbatxon filed In: l, 1900) (NoModel) v.. o. 2. MMM t T m m ifm 7 s v10. m m .v n Y w m Mw A 7 Y yla et. n e t a P S E N m P E 9 L 1 D E 1 C R T.. r m a m A M M B F m .l m mm M. M w n m C m MK Q m w -ljl l ,mw A 4.Ar////zyl////V//f//f//l//AJ//fv l .Y 6. ha Km 3 3 y n 6, D W n mi u m Mn am w%.

M. l. BAIRD,

SWITCHBOAHD FUR TELEPHONES.

(Applicadinn led Har. 1, 1900.)

No. 656,336. Patented Aug. 2|, |900.'

(No Model.) 7 Sheets-Sheet 3.

D L' U Hfy i I TH: Nonms PETERS co nuofurno., wnmNaToN. n. c.

No. 656,336. Patented Aug. 2|, |900.

M. |.BA|RD.

SWITCHBOARD FOR TELEPHONES.

\ (Application led Mar. 1, 1900.)

7 Smets-Sheet 4.

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WITNESSES:

ma Nonms Pneus oo., Puma-umn.. wAsmNcn'cN, n. c.

No. 656,336 Patented Aug. 2l, |900` M. lrBAIRD.

SWITCHBOARD FR TELEPHONES.

(Application filed Mar. 1, 1900.) (lo Model.) 7 Sheets-$heet 5WITNESSES:

www Y? Phatented Aug. 2|, |900.

mf. Amn. SwLEQLHcB'OARD FUR TELEPHUNES.

' (Application led Mar. 1, 1900.) l (No Model.) 7 Sheets-Sheet 6.

MINI. im! 1 im mm@ HIIIIHIH wrrNEssEs:

co, PMo'raLlTHo.. wAsnmn Patented Aug. 2l, i900. l. BMM).

SWITCHBOARD FOR TELEPHUNES.

(Application led Har. 1, 1900.) (No Model.) 7 Sheets-Shad 7.

INV-ENTQR mM Att'y.

lNITED STATES PATENT FFICE.

MILTON I. BAIRD, OF GLENFIELD, PENNSYLVANIA.

SPECIFICATION forming part of Letters Patent N. 656,336, dated Augustai, ieo'. Application filed March 1, 1900. lSerial No. 6,914. (Nomodel.) i

T0 all whom t may concern/f Beit known that I, MILTON I. BAIRD, acitizen of the United States, residing at Gleniield, in the county ofAllegheny and State of Pennsylvania, have invented or discovered certainnew and useful Improvements in Switchboards for Telephones, of whichimprovements the following is a specification.

In anapplication filed December I, 1899, Serial No.7 38,836, I havedescribed and shown certain improvements in switchboards for telephones,said improvements consisting, generally stated, in means whereby theplug may be automatically shifted from operative position, such movementbeing regulated. The invention described herein relates to certainfurther or additional improvements, having for their object aconstruction and arrange-y ment of parts whereby all the connectionsnecessary to bemade to connect and disconneet two subscribers, exceptthe insertion of the plugs, are effected automatically and in propersequence on the removal or replacing of the receivers of the subscribersor the ringing of the bell, as the case may be.l Y In general'terms theinvention consists in the construction and combination substantially ashereinafter described and claimed. In the accompanying drawings, forminga part of this specification, Figure l is a side elevation of a socketor jack forming a part of a telephone-switchboard. Fig. 2 is a sectionalelevation of the same. Fig. 3 isasectional plan view. Fig. 4i is a viewsimilar to Fig. 1, showing a lamp-indicator and its controlling-switch.Figs. 5 and 6 are diagrammatic views illustrating the operation of theconstruction shown in Figs. l, 2, and 3. Figs. 7, 8, and 9 arediagrammatic views illustrating a modification desirable where thecircuit-breaker in the circuitof the controllingmagnet is closed on theremoval of the receiver and remains closed until receiver is returned tonormal position. -FigsIO and 11 are diagrammatic views illustrating aconstruction wherein theposition is not employed. Figs. 12 and V13 aredetail views of plugs. Figs. 14, l5, and 16 are diagrammatic viewsillustrating the operation of my improvements.

In the practice of my invention the switchboard is formed by or consistsof a series of jacks or sockets, dependent upon the number ofsubscribers. Each jack orsocket is formed of wood or other insulatingmaterial and has attached thereto springs l In and 2 2a, provided attheir free ends with fingers projecting through the walls ofthe socket,so as to make contact with the surface of the plug 3 when inserted. Apush-rod 4 is arranged within the socket, so as to bear on the end ofthe plug and shift the same outwardly. This rod is actuated by a spring5, surrounding the rod and bearing at its ends against a collar 6 on therod and a shoulder or abutment on the socket. In order to regulate theoutward movement of the push rod and plug, a piston 8 is formed on orconnected to the rear end of the rod, said piston being arranged with acylinder 7. The pist-on or cylinder, or both, are so constructed, as byports or otherwise, as not to obstruct or interfere with the easy inwardmovement of the push-rod, but to so restrain its outward movement whenactuated by the spring that such movement will be comparatively slow andregular. The outward movement of the push-rod is controlled by a toothI2 on an arm 10, adapted to be shifted by the armature 11 of the magnet9, which is included in the snbscribers call-circuit. The tooth engageswhen the armature is denergized one or the other of shoulders o1`abutinents 13, 13a, and I3b in the push-rod. These shoulders orabutments Willbe termed in describing the operation the normal,77supervisory, and talking shoulders, respectively.

The indicator may be formed by a plate or disk 18, carried by a rod 19,attached to the armature 1l in such manner that when the armature isattracted by the magnet the disk will be shifted in front of an openingin the front plate of the switch board,` or, if desired, a smallelectric lamp 18a may be arranged in visible position adjacent to thejack or socket, as shown inv Fig. 4. When using the lamp, amake-and-break mechanism 20, adapted to be opened and closed by thearmature 11, is arranged in the lamp-circuit. As shown in Fig. et, themovable member of the make-andg-break mechanism may be formed by thearmature l1.

In some systems the subscribers call-switch is connected so as to beclosed only momen- IOO `tarily, as during the ringing of the bellorduring the releasing movement of the receiver-arm. In such systems theconstruction shown in Figs. 2, 3, 5, and Gis preferred. In

describing the operation it will be supposed p indicating by itsposition that the parts are v in normal position.

When a subscriber takes down his receiver or otherwise closes thecallcircuit,fthe armature 11 will be shifted, raising the tooth 12 fromin front of shoulder 13, thereby permitting the push-rod to be movedoutward. This movement of the rod holds the armature, and `consequentlythe indicator, in call position. Inresponding to the call the operatorwill insert a short plug 3a in the calling subscribers jack or socket,so that the push-rod Will be shifted only suiiciently far to permit the`tooth to drop into engagement with the talking shoulder or abutment13", thereby avoiding the ringing of the calling subscribers bell.Having ascertained the numberiof the party Wanted, the operator pushes along plug 3 into the propper jack or socket, thereby shifting thepush-rod inward until thesupervisory shoulder or abutment 13a has passeda short distance beyond the tooth 12,'thereby closingthe call-circuit ofthe party Wanted. After the plug has been pushed in it is released, sothat the spring 5 can push the `rod out until the shoulder 13a 'en gagesthe tooth 12. During the Whole or a portion of this outward movement ofthe push-rod and plug the bell of party called will be rung; but theringing will cease as soon as the tooth 12 engages supervisory shoulder13a. When the party called lifts the receiver or otherwise closes hiscall-circuit, the magnet .9 will be energized, momentarily shifting itsarmature and lifting the tooth 12 from shoulder 13, so that the push-rodwill again move out until the tooth 12 engages the talking-shoulder 13b.As soon as the connected parties hang up their receivers or otherwiseclose their signal or call circuit, the tooth 12 of both jacks orsockets will be shifted momentarily from the shoulders 13b and thepush-rods will move outward until the teeth 12 engage normal positionshoulders 13. These outward movements will not push the plugs entirelyout of the jacks or sockets, but their great projection will indicatethat the parties have finished their conversation. If the operatorshould fail to remove the plug beator an additional indication.

In some systems the call-circuit is closed on the removal of vthereceiver and remains closed until the receiver is again hung up. In sucha system the armature is provided with or is adapted to operate twoteeth or detents 12' and.12", and the push-rod is provided with'twoshoulders or abutments 13c and 13d, as shown in Figs. 7, 8, and 9.several parts are shown in normal position in Fig. 7. When a 'subscribercloses his signal `orcall circuit, thereby energizing magnet 9,

tooth 12a will be raised from shoulder 130, permitting the rod to moveout until said shoulder engages tooth 12b, which Was moved to operativeposition simultaneous with the shifting of tooth 12a from operativeposition. The operator now inserts the short plug 3 into the jack of thevcalling subscriber, forcing back the .push-rod `until the tooth 12bengages shoulder 13d, when the plug Will be in talking position. Havingascertained the number desired, the operator inserts a long plug 3 inthe proper jack or socket, thereby forcing the push-rodin until shoulder13d has passed beyond tooth 12a. The plug is now released and thepush-rodmoves out until the shoulder 13d engages tooth 12a, the magnet 9being denergized. During the outward movement of the rod to engagementwith tooth 12a the called subscribers bell will ring. By the closing'ofthe call or signal circuit 'of such subscriber, due to the removal ofhis receiver or by other means, the magnet 9 of the jack or socket ofsuch 'called subscriber Will be energized, thereby shifting tooth 12aout of and tooth 12b into the path ot' movement of the push-rod, whichwill move out into engagement with tooth 12b, thereby shifting the plugto talking position. When'the subscribers hang uptheir receivers orotherwise break their signal-circuits, the magnets 9 willbecome'denergized, thereby shifting the'teeth 12b out of engagement withshoulders 13d and moving th'eteeth 12a into the path of movement ofshoulders 13. When released from The IOO

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teeth 12b', the .push-rods will move out until l shoulders 13c engageteeth 12a, or to normal position.

In some systemsthe supervisory'positionis not employed, and in such'cases `the rod 4.- will be held onlyin normal and talking positions byshoulders 13 and 13b engaging the tooth 12, as shown in Figs. 10 and 11.The

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construct-ions shown in Figs. 5, 6, 10, and 11 In describingthe circuitsand theoperation of my improvement it will be supposed thatl the callingsubscriber A has rung lup central and removed the receiver fromthe hook,:as shown in Fig. 14. As soon as centralreceives the call the short ortalking plug 3 will be inserted into the proper jack, so that terminalsor springs 1 and 2a willbear uponitlhe portions a and c of the plug,thereby partially completing the talking-circuit for A to the calledparty. Central `then inserts-a plug 3 -in the properjackfor the calledsubscriber B to the full exten t, so that the terminals l 1EL will bearupon the portion c and the terminals 2 2a will contact with the portionb of the plug, thereby completing the ringing-circuitto B, asshown inFigs. 8, 11, and 14. This circuit consists in starting from thegenerator O at central of the wires 24 and 25, terminal la, portion c ofplug 3 at B, terminal 1, wires 26 and 27, call-bell at B, switch formedin part by lever 28 or controlled by thel lever, Wire.29, terminal 2a,portion b of plug, terminal 2, and wires 30 and 3l to generator atcentral. As the terminals 1 1a and 2 2 are in contact with the portionsc and b only during the time the plug is moving from its inmostposition, as shown in Fig. 14, until arrested by contact of the detentwith shoulder 13b, the ringing of the Bs bell will occur only duringsuch movement. The ringing-circuit from central to A is the same as thatto B; but as the short talkingplug 3a, which the operator placed in thejack connected to A, will not connect the terminals 1 1a and 2 2a, asdescribed, As bell will not be rung when B is called. The plug ct at Bwill remain in supervisory position (shown in Fig. 15) after the ringingof Bs bell until Bs receiver is removed from the hook. On the removal ofthe receiver the movement of the lever 28 will break the ringing-circuitand come into contact with terminals 32 and 33 to close thetalking-circuit. This circuit consists of the usual connections at bothstations to the line-wires 26 and 29, which are connected to terminals 1and 2a at central. As the magnet 9 is bridged across the line-wires itwill be excited and raise the detent 12 as soon as the lever 28completes its movement, thereby permitting the plug 3 to be forced out.During this outward movement of the plug the portion a thereof willcontact with the terminal 2a and at the same time bring the insulatedportions of the plug into contact with terminals 2 and la. As thecontact of terminal 2a with portion a of the plug will occur beforeshoulder 13b is in line with the detent and as the magnet 9 has acomparatively-highresistance it will be, in eect, cut out, so as topermit detent 12 to drop and hold the plug in talking position, as shownin Fig. 16. The talking-circuit in the central station consists instarting from line-wire 29 at subscriber A of terminal 2, portion a ofplug 3a, wire 34, portion a of plug 3, terminal 2, to line-wire 29,leading to subscriber B, linewire 26 from subscriber B, terminal 1,portion c of plug 3, wire 35, portion c of plug 3,

andterminal 1 to line-wire 26, leadingito subscriber A. V

It will be readily understood by those skilled in the art that othermeansmay be employed for controlling the action of the actuatingspring 5and that by making the `tension of the spring light the controllingmeans, such as thecylinder 7, may be omitted, the principal function ofthe controlling means being to aiford opportunity for the teeth on themagnets 9 to engage the several shoulders on the push-rod and to avoidjars or shocks to the delicate mechanism.

In the majority of switchboards the change of circuits, the ringing ofthe bell of the call subscriber, and the disconnecting of the plug from`the talking-circuit after the subscriber has finished talking are allmanually accomplished by the action of the operator, often causingexasperating delays to the subscriber by reason of the neglect of theoperator to immediately disconnect and answer the new calls.

It is characteristic of my improvements that they are readily applicableto all the various systems of telephoning now in use, such as themagneto-generator system or any of the various forms of thecentral-battery system, with or without the supervisory signals nourused in some systems to indicate that the called subscriber is ready fortalking. It is also characteristic of my improvement that the automaticringing of the subscribers bell, the cutting out of the generator orbell-ringing circuit, the setting of the plug preparatory for thereception of the supervisory signal when used,the reception ofthesupervisory signal, the automatic change of circuit from supervisoryto talking position, and the automatic change of circuits from talkingto normal position are edected automatically by the action of thesubscriber or subscribers without the action of the operator other thanthe mere insertion of the necessary plugs into the proper jacks orsockets.

I claim herein as my invention- 1. In a telephone-switchboard, thecombination of a jack or socket, a plug, means for shifting the plug,and means for checking the outward movement of the plug and holding thesame in two or more positions, substantially as set forth.

2. In a telephone-switchboard, the combination of a jack or socket, aplug, means for shifting the plug, mechanism for holding the plug innormal or non-operative position and mechanism for holding the plug intalking position, substantially as set forth.

3. In a telephone-switchboard, the combination of a jack or socket, aplug, means for shifting the plug, and means for holding the plug incalled or supervisory and talking positions, substantially as set forth.

4. In a telephone-switchboard, the combination of a jack or socket, aplug, means for shifting the plug, means controlled by the IOO Izzovsubscriber for holding the plug in normal, called or supervisory andtalking positions, substantially as set forth.

5. Ina telephone-switchboard, the combination of a jack or socket, aspring-actuated rod for shifting the plug, means for checking themovements of the push-rod and holding the same in tWo er more positionsand a magnet in a circuit controlled by the subscriber for controllingthe detent mechanisms, substantially as set forth.

6. In a telephone-switchboard, the combination of a socket or jack, aspring-actuated rod for shifting the plug, a series of two or moreshoulders or abutments on the pushrod, andan electrically-controlledtooth for engaging said shoulders or abutments, substantially as setforth.

7. In a telephone-switchboard, the combination of a socket or jack, aplug, means for shifting the plug, means for checking the movements ofthe plug, and means lfor regulating the rate or speed of the plugmovements, substantially as set forth.

8. In a telephone system, the combination of tWo sockets or jacks, meansin each jack or socket for shifting the plugs, detent mechanismscontrolling the plug-actuating mechanisms and arranged to hold the plugsin normal, supervisory and talking positions, a plug provided with astop or shoulder to prevent its movement beyond talking position and aplug constructed to enter the socket beyond supervisory position,substantially as set forth.

In testimony whereof I have hereunto set my hand.

MILTON I. BAIRD. Witnesses:

DARWIN S. WoLooTT, F. E. GAITHER.

